Saturday, June 27, 2009

GOING ELECTRIC PART 15: Securing the battery platform

The battery platform is already pretty secure for lateral movement with the braces and also being butted up against wood bulkheads on both sides. I also added a strip of wood to the forward edge and side as an extra precaution to prevent the battery from sliding. Especially onto the motor. Before I secure the platform to the stringers I need to figure out how I will layout the batteries. For this I cut some cardboard pieces the same size as the 8A4D batteries and played with their layout on the platform.

The advantage of placing the batteries in the location where the engine was is that the trim of the boat in the water should be about the same and also keep the wire runs as short as possible. Using cardboard cutouts of the same dimensions as the 8A4D AGM batteries I will be ordering I decided on the arrangement above. This seemed to be the best arrangement for maintenance and weight distribution and wire runs. The 8A4D batteries weigh 129 lbs each which after removing the 424 pound Westerbeke 27, starting battery, diesel fuel and associated components probably gives a slight weight advantage to the electric propulsion system. One of the reasons I choose to place the battery on the left side in the above photo is to provide the proper balance for weight distribution. Next to that battery is the now empty diesel fuel tank. So this battery will help provide the needed weight on the starboard side to balance out missing weight of the diesel fuel and keep the trim of the boat about the same.

The above photo shows how I secured the battery platform to the stringers. I used stainless steel lag bolts and washers. I drilled pilot holes and simply screwed the lag bolts into the stringers. You can see I made an outline of the stringers on the platform to make it easier to find the center to place the lag screws.
GOING ELECTRIC TIP: When working in confined areas like this it is useful to have a small fan circulating air to keep you comfortable while working.
With the platform now securely installed and the battery layout planned the next step is to install the batteries.


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